Methods of manufacture are disclosed in Ott et al., 2000 (The Adjuvant MF59: A 10-year Perspective. Vaccine Adjuvants: Preparation methods and Research Protocols [Methods in Molecular medicine, Vol. 42, Chapter 12, p211-228], Ott et al., 1995 (MF59—Design and Evaluation of a Safe and Potent Adjuvant for Human Vaccines: Vaccine Design, the Subunit and Adjuvant Approach [Pharmaceutical Biotechnology volume 6] eds. Powell & Newman, WO06/100110A1 and Lidgate et al., 1992 (Sterile Filtration of a Parenteral Emulsion. Pharmaceuticals Research 9(7): 860-863).
Oil in water emulsions can be used in vaccine/immunogenic compositions as adjuvants. As these emulsions are administered to humans it is necessary that the emulsions are sterile. Oil in water emulsions used as adjuvants are submicron emulsions and the oil droplets are sufficiently small to be sterile-filtered through 0.2 μm filtered. It is an object of the present invention to provide a process for the production of submicron oil in water emulsions and in particular filtration of oil in water emulsions.